Sectional and longitudinally adjustable surfboard fin assembly

ABSTRACT

A SURFBOARD FIN ASSEMBLY INCLUDES A LONGITUDINALLY ADJUSTABLE FIN SECTION MOVABLE MOUNTED WITHIN AN ELONGATED CHANNEL FORMED BY A FIN BASE SECTION. THE FIN BASE SECTION HAS TAPERED EXTERIOR SIDE WALLS SIZED FOR WEDGING ENGAGEMENT WITH TAPERED INTERIOR SIDE WALLS OF A MOUNTING BOX. THE FIN BASE SECTION CAN BE SELECTIVELY INTERLOCKED WITH THE FIN SECTION BY USE OF A RETAINING PLATE THAT IS SLIDABLY COUPLED TO THE FIN BASE SECTION AND IS LOCATED IN THE   ELONGATED CHANNEL. THE RETAINING PLATE HAS A POSITIONING GROOVE FOR RECEIVING A PORTION OF THE FIN SECTION.

y 1971 K. o. POPE m. E'I'AL 3.5

SECTIONAL AND LONGITUDImLY ADJUSTABLE SURFBOARD FIN'ASSEMBLY FiledApril 1. 1969 INVENTORS. KARL D. POPE III THOMAS H; MOREY ROBERT R.TIERNEY A TTORNE Y8 United States Patent O 3,579,681 SECTIONAL ANDLONGITUDINALLY ADJUST- ABLE SURFBOARD FIN ASSEMBLY Karl 1). Pope III,6377 Clemens St., and Thomas H. Morey, 36 Lincoln Drive, both ofVentura, Calif. 93003, and Robert R. Tierney, 412 Mallory Way, O al,Calif. 93023 Filed Apr. 1, 1969, Ser. No. 811,810 Int. Cl. A63c /00 US.Cl. 9-310 7 Claims ABSTRACT OF THE DISCLOSURE A surfboard fin assemblyincludes a longitudinally adjustable fin section movably mounted withinan elongated channel formed by a fin base section. The fin base sectionhas tapered exterior side walls sized for wedging engagement withtapered interior side walls of a mounting box. The fin base section canbe selectively interlocked with the fin section by use of a retainingplate that is slidably coupled to the fin base section and is located inthe elongated channel. The retaining plate has a positioning groove forreceiving a portion of the fin section.

This invention relates to surfboard fin assemblies and more specificallyto a surfboard fin assembly that can be removably mounted within amounting box and includes a fin section that can be longitudinallyshifted to different positions.

BACKGROUND OF THE INVENTION Conventional surfboards ordinarily have askeg or fin rigidly fixed to the rearward undersurface portion of thesurfboard. While this typical arrangement serves to perfectly align thefin and stabilize the surboard the resulting lack of flexibility makesits storage and handling very cumbersome. Restriction to a single findesign also minimizes the range of maneuvers that can be undertaken bythe surfer.

In order to overcome the above outlined disadvantages of fixed fins theconcept of an easily removable surfboard fin was developed as is fullydescribed in U.S. Pat. 3,422,471 to Morey et a1. issued Jan. 21, 1969. Arelated approach concerning a demountable and interchangable surfboardfin is disclosed in co-pending application U.S. Ser. No. 737,413 filedJune 17, 1968, now Pat. No. 3,516,099 entitled Mounting Structure forRemovable Surfboard Fin.

In order to further increase the versatility of demountable andinterchangable surfboard fins an approach has been suggested whereby theentire surfboard fin can be longitudinally slid within a mounting boxand can be interlocked with the box at a selected position. By thisarrangement a surfer can adjust the fin position relative to thesurfboard trailing edge. The fin however is of unitary construction,tends to jam while sliding, and, is difficult to dismantle from the box.

As shall be fully explained the surfboard fin assembly of this inventionis sectional so that a fin base section can remain directly secured tothe mounting box while a fin section is longitudinally slid within thefin base section.

BRIEF SUMMARY OF THE INVENTION Briefly stated this invention comprehendsa surfboard fin assembly including a fin base section with an elongatedchannel and a fin section slidably coupled to the fin base section. Thefin section has a positioning tongue sized for insertion into thechannel.

The interior sidewalls of the fin base section are formed with a pair ofelongated notches that receive the marginal edges of a retaining plate.The plate is formed with a positioning groove for receiving thepositioning tongue. When the positioning tongue is inserted in thepositioning groove the fin section can be slid to a desired location andlocked against the fin base section. In order to lock the fin section inplace an enlarged intermediate section of the fin section and theretaining plate are urged towards one another to exert clamping force ona portion of the fin base section located between the retaining plateand intermediate section.

The exterior sidewalls of the fin base section are tapered to wedgetightly against complementary shaped interior sidewalls of a mountingbox. When the fin base section is tightened against the mounting box andthe fin section is tightened against the fin base section then thesurfer is capable of performing various surfing maneuvers with assurancethat the fin assembly is accurately positioned and perfectly balanced.

BRIEF DESCRIPTION OF THE DRAWINGS The numerous benefits and uniqueaspects of the present invention will be fully understood when thefollowing detailed description is studied in conjunction with thedrawings in which:

FIG. 1 is a perspective, exploded view showing a fin assemblyconstructed in accordance with the present invention prepared forincorporation into the undersurface of a surfboard;

FIG. 2 is a sectional, exploded view taken along line 22 of FIG. 1, aswould be viewed if the various components of the fin assembly werevertically exploded from an assembled position; and,

FIG. 3 is a sectional view of the surfboard, mounting box, and finassembly taken along 22 of FIG. 1, as

would be viewed if these components were fully assembled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1a sectional and longitudinally adjustable surfboard fin assembly 10 isshown exploded downwardly from a conventional surfboard 11 that isformed with an elongated opening in its rearward undersurface sectionfor firmly and permanently bonding a mounting box 12. Mounting box 12has an elongated cavity 13 and tapered interior sidewalls 14. Securingmeans for removably securing box 12 and fin assembly 10 togetherincludes forwardly and rearwardly positioned threaded sockets 15, onlythe rearwardly disposed one of which is shown.

A fin base section 16 is centrally formed with an elongated andlongitudinally extending channel 17. Fin base section 16 includes a pairof side shoulders or blocks 18 and 19 which, in part, define elongatedchannel 17. As shall be subsequently explained portions of side blocks18 and 19 not shown in FIG. 1 define portions of a pair of notches. Theexterior sidewalls 20 and 21 are tapered in order to be of complementaryshape relative to the mounting box interior sidewalls 14. When finassembly 10 is secured within box 12 then the complementary inten'orsidewalls 14 and exterior sidewalls 20 and 21 become wedged together andsnugly interfit to prevent relative motion between box 12 and finassembly 10. The upper portion of fin base section 16 is formedalternately with ribs 22 and recesses 23 that serve to promotelightweightness as well as uniform cooling of the plastic materialfollowing an injection molding fabrication treatment.

The forward and rearward sections of fin base section 16 includesecuring openings 24 and 25 for receiving securing screws 26 and 27structured to cooperate with threaded sockets 15.

(d) an elongated retaining plate having a pair of longitudinallyextending marginal edges slidably positioned in the notches, the platebeing located in the elongated channel and having a longitudinallyextending positioning groove for receiving the positioning tongue;

(e) locking means including the retaining plate for selectively lockingthe fin base section and fin section together when the fin section hasbeen longitudinally moved to a desired position;

(f) a mounting box having an elongated cavity sized to receive the finbase section; and,

g) securing means for securing the fin base section and mounting boxtogether.

7. The structure according to claim 6, including:

a slot formed through at least one end of the fin base section, the slotbeing aligned with the notches to facilitate selectively admitting andwithdrawing the retaining plate from the channel;

tapered longitudinally extending exterior side walls formed on the finbase section; and,

References Cited UNITED STATES PATENTS 3,287,754 11/1966 Price et a1.9-310 3,305,881 2/1967 Meyerhofer 93 10 3,323,154 6/1967 Lambach 9-3 103,422,471 1/1969 Morey et a1. 9-310 15 MILTON BUCHLER, Primary ExaminerP. E. SAUBERER, Assistant Examiner US. Cl. X.R.

